Nitro-trifluoromethyl-aryl amines and process for making them



Page! Aug. 27, 1940 UN 1TB!) sm-ssj V N ITBO -TRIi TUOBZ METH I L-AR 2,212,325 PATENT OFFICE YLAMINES AND rnocnss ron MAKING THEM Herbert W. Daudt, Wilmington, Del., and Haroldv E. Woodward, Penna Grove, N. 1., assisnors to E. I. du Pont de Nemours a Company, Wilmington, DeL, a corporation of Delaware No Drawing.

Application December 31, 1937, Serial No. 182.800

is c aims. (01. zoo-s11) 15 It is among the objects of the present invention to provide N-substltuted nitro-amino benzotriiluorides which are obtainable by animating a nitro-halo-benzotrifluoride containing at least one and not more than two nitro groups and not 20 more than two trifluoromethyl groups, in which at least one ortho or para position to halogen is occupied by one oi the group nitro or trifluoromethyl- The aminating in which halogen is displaced by the amide radical is done by the action of an amine having the general formula in which R1 is hydrogen, 'alkyl or aralkyl and Re is alkyl, aryl or aralkyl. When R: is aryl, the aryl may be benzene or naphthalene, which aryl is unsubstituted or is substituted as by alkyl, alkoxy, hydroxy, halo, amino, acylamino or azo-benzene. Another object of the invention is to provide processes for producing the compounds. Still other objects of the invention will be apparent from the following description.

The objects of the invention are attained in general by aminating nitro-halo-benzotrifluorides with alkyl, aryl or aralkyl amines.

The invention will be more fully set forth in the following more detailed description which in- 45 cludes examples that are given as illustrative embodiments of the invention and not as limitations thereof.

Example 1 was removed by filtration. It comprised methylamine hydrochloride.

The yellow colored filtrate was evaporated to dryness. Yellow crystals, which upon purification from a suitable solvent melted in the range 6889 C., remained. The product consisted essentially of 3,5-dinitro-N-methyl-2-amino benzo- .trifluoride which is represented by the formula 's The above product was used to dye acetate silk. Yellow shades were obtained.

3,5-dinitro-2-chloro-benzotrifluoride is a crystalline compound melting in the range 57 to 59 C. and can be made by the dinitration of orthochloro-benzotriiiuoride.

Example 2 3.5 dinitro 2 chloro benzotrlfluoride (200 parts) were dissolved in benzene (6500 parts) and the solution treated with dimethylamine gas under operating conditions similar to those used in Example 1.

There was obtained a yellow crystalline product which, upon purification, melted about 55 C. This product comprised 3,5-dinitro-N-dimethylz-amino-benzotrifluoride. Acetate, silk dyeings were yellow in shade.

In another operation a pressure of 15-30 lbs.

per sq. inch was maintained in a closed vessel. The same product was obtained.

Example 3 A dinitro-N-methyl-fii-amino benzotrifluorlde was similarly prepared by treating a dinitro-mchloro-benzotrifluoride with methylamine under conditions similar to those of Example Example 5 3,5- dinitro-N-ethyl 4 amino-benzotrifluoride was obtained by condensing 3,5-dinitro-4-chlorobenzotrifluoride (prepared by dinitrating pchloro-benzotrifluoride) with ethylamine by a procedure similar to that of Example 1.

Example 6 5-nitro-2-chloro benzotrifluoride (30 parts) was added to a solution of methylamine (33 parts) in ethyl alcohol (300 parts) which was contained in a copper lined autoclave. After the addition of 0.5 part cuprous chloride to the mixthoxy-diphenylamine which is represented by the ture, the autoclave was closed and the charge of reactan was heated to l15-120 C. during an hour an was then maintained in this temperature range for eight hours.

The cooled reaction charge was filtered. The solvent was removed by evaporation. The residue was subjected to steam distillation for half an hour. The solid material in the residue was removed by filtration and subsequently subjected to crystallization from a suitable solvent. 5- nitro-N-methyl-2-amino-benzotrifiuoride was obtained.

Example 7 S-nitro-N-dlmethyl 4 amino-benzotrifluoride was prepared by amidating 8-nitro-4-bromobenzotrifiuoride with dimethyl-amine under the conditions of Example 8.

Example 8 8,5-dinitro-6-chloro-benzotrifiuoride (20 parts) was dissolved in anhydrous ether (200 parts) and aniline (20 parts) was added during a period of 5 minutes. The resulting solution deposited a crystalline mass upon standing at room temperature. After 24 hours standing of the reaction mass at room temperature the crystals were removed by filtration. They were identified as aniline hydrochloride.

The filtrate was extracted three times with about 100 parts of 5% hydrochloric acid. An orange red crystalline mass resulted upon the removal of the solvent by evaporation. These crystals, upon purification by crystallization from alcohol, melted at approximately 137 0. They dyed acetate silk orange shades of yellow.

The product comprised 4,6-dinitro-2-(trifiuoromethyl) diphenylamine which is represented by the formula Example 9 The procedure 01 Example 8 was applied to the preparation of other diphenylamine derivatives by condensing the same dinitro-chloro-benzotrifiuoride with ring substituted derivatives of aniline. In all cases, the aryl amine was used in molecular proportions that were at least twice those of the dinitro-chloro-benzotrifiuoride. Unless otherwise stated, the reactions were carried out under essentially the same temperature conditions. The hydrochlorides of the aniline derivative (starting material) and the substituted diphenylamine, per se, were isolated in essentially the same manner. All of the products which are shown below dyed acetate silk shades of yellow or orange.

(0) 4,6 dinitro 2 (trifiuoromethyl) 4' hydroxy-diphenylamine which is represented by the formula V N 0 H Q Q Fa was prepared by aminating for 24 hours with pamino phenol in ether. The melting range of th purified product was about 120 C.

(11) 4,6, dinitro-2- (trifiuoromethyl) 4' meformula NOI L was prepared by aminating 12 hours with anisidine in benzene medium. The melting range of the purified product was about 105 C.

(c) 4 (4',6'-dinitro- 2' (trifiuoromethyl) diphenylamine) -azo-benzene which is represented by the formula was prepared by aminating 48 hours with pamino azo benzene in ether medium. The melting point was approximately 140 0.

Example 10 Example 11 A mixture of 3,5-dinitro-2-ehloro-benzotrifluoride (100 parts) xylene (2500 parts) and mono ethyl aniline (600 parts) was boiled under a reflux condenser for 14 hours. The cooled reaction mass was extracted four times with 20% hydrochloric acid. The xylene was evaporated from the non-aqueous solution. The residue consisted of N-ethyl-4,6-dinitro-2-(trifluoromethyl) -diphenylamine. When purified by crystallization from alcohol it melted at approximately 135 C. The product is represented by the formula NO: CIHI Example 12 Alpha-naphthyl- (4,6-dinitro-2- (triiiuoromethyl) -phenylamine was prepared by condensing 3,5-dinitro-Z-chloro-benzotrifluoride with alpha naphthylamine under conditions like those of Example 8. The product dyed acetate silk orange-yellow shades and is represented by the formula Alpha-naphthylamine hydrochloride was a byproduct.

The use of beta naphthylamine in place of alpha naphthyl-amine produces an isomeric compound. By using a. 4-a1koxy-1-naphthylamine instead of alpha naphthylamine a product represented by the following formula was produced. W.

O N N Alkoxy F. Example 13 The product dyed acetate silk light yellow shades. The reduction of a portion of this product produced 4-amino-2-(trifiuoromethyl)-4'- ethoxy diphenylamine. The last named compound gave a blue color when its acid solution was treated with ferric chloride. Its diazotized product formed colored compounds when coupled to the following coupling intermediates.

Coupling component Color 0! product R-salt Anilide oi b-oxy na htboic acid Alpha naphthylam e Reddish blue color. Blue color.

4 nitro 2 (trifluoromethyl) diphenylamine was prepared in the manner described in the foregoing example by condensing 5-nitro-2-chlorobenzotrifiuoride with aniline.

By using an equivalent amount of alpha naphthylamine instead of p-phenetidine in Example 13, 4-nitro-2-(trifiuoromethyl)-phenyl alpha naphthylamine was prepared.

By using an equivalent amount of 4-methoxyl-naphthylamine instead of p-phenetidine in Example 13, 4-nitro-2-(trifluoromethyl) -phenyl-4- methoxy naphthylamine was prepared.

The latter two compounds were reduced to the corresponding amino derivatives. These amines were diazotized and coupled to various azo dye coupling components among which were those mentioned in Example 13. The amino compounds are represented by the formulae Example 14 A mixtureof 5-nit'ro- -2-chloro-benzotrifluoride 75; (20 parts) ethyl aniline (60 parts) and xylene series.

(800 parts) was boiled for 36 hours under a reflux condenser. N-ethyl-4-nitro-2-(trifluoromethyD-diphenylamine was produced. Its mula is Example 15 N-beta ethanol aniline and di-ethanolamine.

Example 16 Still other nitro-(trifluoromethyl) diphenylamines were prepared by condensing 4-nitro-2- chloro-mnzotrifiuoride with p-phenetidine, o-anisidine, 2,5-dimethoxy aniline, benzidine, dianisidine, N-beta ethanol aniline and di-ethanolamine.

Nitro-halo-benzotrifiuorides in which at least one nitro group or one CF3 group is ortho or para to-the .halogen can be'aminated with amines. Preferably, one of these groups nitro and trifiuoromethyl is ortho and the other is para, or both groups are ortho to the active halogen. The benzene nucleus may be substituted by one or two nitro groups, or by one or two CF: groups. Any halogen can be used, for example, chlorine, bromine, iodine or fiuorine.. Other substituent groups such as alkoxy and additional halogen may also be present. If the starting material contains more than one halogen in positions which are ortho or para to .a nitro or CF; group it is possible to replace one or both of the halogens with an N-substituted amino group.

As aminating agents primary alkyl amines, primary aryl amines, primary aralkyl amines, N-mono alkyl arylamines and di-alkylamines can be used in which the alkyl groups preferaby contain not more than 5 carbons, and the aryl groups are from the benzene and naphthalene These alkyl and aryl groups may be unsubstituted or they may be substituted as by halogen, amino, alkyl, primary' or secondary amino or acyl amino, alkoxy and hydroxy may be present in the alkyl group or in the benzene or naphthalene nuclei. The azo group may also be present in the aryl nuclei, forexample azobenzene and azo-naphthalene groups.

As examples among the many other aminating agents which may be used meta-amino-monoethyl aniline, para-amino-dimethylaniline, or-

thoand para-toluidine, para-bromo aniline and meta-chloro aniline are mentioned.

Diluents other than those described in the ex amples, may be used. Preferably, the diluent should be inert to both of the reacting components. As examples of other solvents the following are mentioned: Methyl alcohol, ethyl alcohol, ether, chloroform, benzene, toluene, xylene and other hydrocarbon solvents. The presence of catalysts, such as coppersalts, are advantageous in carrying out some of the amidations at lower temperatures and pressures than would otherwise be required. Inert hydrogen halide acceptors, such as tertiaryabasesnfoLexampleWe dinithyl aniline may also be added.

a The temperatures of the reactants may b for- nitro-N-dialkyl-amino-benzotrifluorides,

varied over a fairly wide range depending upon the reactivity of the starting nitro or dinitro chloro-benzotrifluoride. Ordinarily, temperatures of l10-180 C. are desirable for the amnation of mononitro-halo-benzotrifluorides and temperatures of 20-150 C. for the amination of dinitro-halo-benzotrifluorides. The basiciw of the amine also has an influence on the choice of the temperature range. The less basic amines in general require h gher temperatures. In gen-' eral, the dinitro-haio-benzotrifluorides react more readily than the mon-nitro-halo-benzotrifluo'rides. The prwsure may be equal to or may exceed the atmospheric pressure. The use of super-atmospheric pressure is of particular advantage when low boiling diluents are used, when the reaction is carried out at relatively high temperatures or when a volatile amine is added to the reaction mass in the form of a gas or vapor.

From the foregoing description it will be evident that nitro-N-alkylamino-benzotrifluoridos,

nitro- (trifluoromethyl) diphenylamines, nitro- (trifluoromethyl) -phenyl-naphthylamines and N- alkyl nitro (trifluoromethyl) diphenylamines have been produced in accordance with the invention by aminating the described mono and dinitro-halo-benzotrifluorides in which CF: and N02 are in one or more of the positions 2, 4 and 6 to chloro, said aminating agents being monoalkyl amines, diallwl amines, primary aryl amines of the benzene series, primary aryl amines of the naphthalene series and N-alkyl aryl amines respectively. These compounds can be represented by the general formula Br l)- pled with coupling components.

Among the preferred embodiments of the invention are the 4-nitro-2-trifluoromethyl-4'-alkoxy-diphenylamines which have properties as intermediates for blue azo dyes. The preferred type is represented by the formula in which X is one of the group consisting of hydrogen and nitro and Y is halogen, hydroxy or alkoxy.

Amidation is the process of treating a halo derivative with an amino derivative and displacing the halogen by an amino group.

thosewhicharerecitedln theannexedclaimsor areimpoced by the prior art.

We claim:

1. As new compounds the members of a group consisting of mono-nitro-N-substituted amino benzotrifluorldes and dinitro-N-substituted amino benmtrifluorldes represented by the formula in which x is one of the group consisting of nitro and trifluoromethyl, Y is one of the group consisting of hydrogen and nitro, Z is trlfluoromethyl when X is nitro and is nitro when X is trifluoromethyl, R1 is one of the group consisting of hydrogen and alkyl having 1 to 5 carbons, R: is one of the group consisting of alkyl having 1 to 5 carbons and aryl, said aryl radicals being members of the benzene and naphthalene series, and Q is one of the group consisting of hydrogen and trifluoromethyl.

2. The compounds in accordance with claim 1 in which R: is an aryl of the benzene and naphthalene saris. I

3. The dinitro-N-substituted amino benzotrifluorides represented by the formula in which X is one of the group consisting of nitro and trifluoromethyl, Z is trifluoromethyl when X is nitro and is nitro when X is trifiuoromethyl, Q is one of the group consisting of hydrogen and trifluoromethyl, R1 is one of the group consisting ofhydrogenandalkylhaving 1to 5 carbons and aryl is a manber of the benzene and naphthalene series.

4. A compound represented by the formula A NO: in which one A is hydrogen and the other A is the group -NH aryl wherein aryl is a radical of the benzene and naphthalene series.

5. A compound represented by the formula I omQmr m1 N0| in which aryl is a radical of the benzene and naphthalene series.

6. A compolmd represented by the formula in which X is one of a group consisting of hydrogen, halogen. hydroxy and alkoxy.

7. A compoimd represented by the formula 8. A compound represented by the formula Q 9. A compound represented by the formula 10. The process which comprises aminating a -3 nitro-halo-benzotrifluoride containing not more than two-nitro groups and not more than two triiluoromethyl groups, and in which at least one of the positions ortho and para to halogen is occupied by one of the group consisting of nitro and trifiuoromethyl, with an amine represented by the formula in which R1 is one of the group consisting of hydrogen and alkyl having 1 to 5 carbons, R: is one of the group consisting of alkyl having 1 to 5 carbons and aryl, the aryl radical being a member of the benzene and naphthalene series, said amination being carried out between temperatures of 20 and 180 C. until a nitro-trifluoromethyl-phenyl-amine is formed.

11. The process which comprises aminating a nitro-halo-benzotrifluoride containing. not more than two nitro groups and not more than two trifluoromethyl groups, and in which at least one of the positions ortho and para'to halogen is occupied by one of the group consisting of nitro and triiluoromethyl, with an amine represented by the formula Aryi in which R1 is one. of the group consisting of hydrogen and alkyl having 1 to 5 carbons, and aryl is a member 01 the benzene and naphthalene series, said amination being carried out between temperatures of 20 and 180 C. until 2. nitrotrifluoromethyl-phenyl-amino is formed.

12. The process which comprises aminating a compound represented by the formula I b-Q-Halogen in which X is one of the group consisting of nitro and trifiuoromethyl, Z is nitro when X is trifluoromethyl and is trifluoromethyl when X is nitro, and Q is one of the group consistin of hydrogen and trifluoromethyl, with an amine represented by the formula in which R1 is one of the group consisting of hydrogen and alkyl having 1 to 5 carbons andaryl is a member of the benzene and naphthalene series, said amination being carried out between temperatures of and 180 C. until a nitrotrifiuoromethyl-phenyl-amine is formed.

HERBERT W. DAUDT'; HAROLD E. WOODWARD. 

